The Three Hundred project: a large catalogue of theoretically modelled galaxy clusters for cosmological and astrophysical applications

Abstract

We introduce the The Three Hundred project, an endeavour to model 324 large galaxy clusters with full-physics hydrodynamical re-simulations. Here we present the dataset and study the differences to observations for fundamental galaxy cluster properties and scaling relations. We find that the modelled galaxy clusters are generally in reasonable agreement with observations with respect to baryonic fractions and gas scaling relations at redshift z = 0. However, there are still some (model-dependent) differences, such as central galaxies being too massive, and galaxy colours (g −r) being bluer (about 0.2 dex lower at the peak position) than in observations. The agreement in gas scaling relations down to 10 13 h −1 M between the simulations indicates that particulars of the sub-grid modelling of the baryonic physics only has a weak influence on these relations. We also include -where appropriate -a comparison to three semianalytical galaxy formation models as applied to the same underlying dark matter only simulation. All simulations and derived data products are publicly available.observed properties of the Intra-Cluster Medium (ICM), the size of the central brightest cluster galaxy and the number and properties of the satellite galaxies orbiting within a common dark matter envelope. Clusters of galaxies can therefore be considered to be large cosmological laboratories that are useful for pinning down both cosmological parameters and empirical models of astrophysical processes acting across a range of coupled scales.Concerted effort, from both observational and theoretical perspectives, has been devoted to improve our understanding of the formation and evolution of galaxy clusters. On the observational side, multi-wavelength telescopes are

TheThreeHundred project: backsplash galaxies in simulations of clusters

“…GadgetX is a modified version of the Gadget3 code, which is itself an updated version of the Gadget2 code, and uses a smoothed-particle hydrodynamics scheme to fully evolve the gas component of the simulations Beck et al 2016). A more extensive, technical description of TheThreeHundred dataset is available in Cui et al (2018).…”

“…Note that for a cluster to be most relaxed, we require ∆r and fs to be minimised, and η → 1 (Cui et al 2017). χDS = 1 corresponds approximately to the Cui et al (2018) definition of dynamical state, such that all of the clusters they denote as 'dynamically relaxed' have χDS > 1.…”

“…Our sample consists of 86 'relaxed' clusters, 86 'unrelaxed' clusters, and 85 with 0.619 < χ DS < 1.030. The hatched bars represent the clusters that are dynamically relaxed according toCui et al (2018); by definition, these have χ DS > 1.…”

The Three Hundred Project: Correcting for the hydrostatic-equilibrium mass bias in X-ray and SZ surveys

“…We, furthermore, investigate an approach proposed almost a decade ago (e.g., Ameglio et al 2009) and recently adopted in observational samples (e.g., Ettori et al 2019): to include directly the pressure, which can be derived from SZ observations out to large radii, within the HE mass equation, under the assumption that clump pressure is close to the isobaric level of the ICM. These goals are pursued with a detailed investigation of the simulated clusters of 'The Three Hundred' Project (Cui et al 2018), analysed at z = 0. The sample employed includes a large number of massive clusters (more than three hundred), comparable only to the MACSIS project (Barnes et al 2017b).…”

Stellar-mass Measurements in A133 with Magellan/IMACS

“…Furthermore, the distribution of stellar material and hot gas within clusters should bear the imprint of key processes shaping galaxy formation. Indeed, observed stellar mass fractions and stellar mass function of cluster galaxies have become valuable benchmarks for testing models of feedback in cosmological simulations of cluster formation (e.g., Martizzi et al 2014Martizzi et al , 2016Bahé et al 2017;McCarthy et al 2017;Cui et al 2018;Pillepich et al 2018;Henden et al 2018). The radial profile of stellar density of the Brightest Cluster Galaxy (BCG), as well as the radial distribution of stellar mass in galaxies are potentially equally powerful constraints on the models (e.g., Martizzi et al 2014;Bellstedt et al 2018).Despite recent progress (Gonzalez et al 2013;Budzynski et al 2012Budzynski et al , 2014Kravtsov et al 2018;Huang et al 2018), the number of clusters with available accurate measurements of the gas mass, stellar mass in galaxies down to dwarf scales, and stellar material in the outer envelope of the central galaxy remains small.…”